Araki is a lock. She’s perfect for MB2. Nippon needs 1 balanced MB and attacking MB perfect for MB1. Shimamura could be that scoring MB. Balanced MB would be a tossup between Okumura and Akutagawa.
For setter, I don’t really think Miyashita is ready for starter. She was a bit messy in world cup. Sato needs to be ready. If not, maybe there is a need to invest in the younger setters like Momii.